Many traditional electronics include buttons, switches, keys, or other types of components as input devices. It is desirable that input devices provide haptic feedback to a user.
Many traditional input devices are mechanical buttons. Mechanical buttons are generally reliable and provide inherent haptic feedback, as a user can often feel the mechanism of the button moving, for example between button positions. However, mechanical switches typically have set haptic outputs or feedback, dictated by their design. Also, as electronic devices have become more space-constrained, mechanical buttons have presented problems and design limitations. Many mechanical switches need a minimum amount of space to operate. For example, a typical dome switch needs about 200 microns of travel for the dome to collapse and close the switch. This is especially problematic in very thin electronic devices.
Pivoting input structures may allow increased haptic design flexibility and may allow the haptics to change with environmental or use conditions. A pivoting button may provide an adjustable haptic feedback to the user. Also, pivoting input structures may greatly reduce required space and particularly travel. Many pivoting buttons travel 10 microns or less when force is exerted thereon. Pivoting buttons can use force sensors to determine when the button is pressed, for example. The force sensor registers a change in capacitance, resistance, current, voltage, or other electrical value when the pivoting button moves or flexes, even though such motion may be very small.
Many pivoting input structures, such as buttons, require physical movement of some portion of the input structure to register an input and/or to trigger haptic feedback of a user input. Although the physical movement of pivoting systems is reduced to that of mechanical systems, a pivoting system that does not require physical movement may combine several advantages of traditional mechanical switches and pivoting input structures. For example, a pivoting system devoid of vertical or inward movement may provide the increased reliability of mechanical buttons with the lower profile and variable haptics of a pivoting system.